Lately was the release of Ubuntu 14.04. I was using 12.04 on my laptop but it was installed with wubi installer. I tried to search for a wubi with 14.04 but didn't find it. Can Is there a way to install 14.04 alongside Windows 7 on one HDD. I had and idea to to upgrade 12.04 to 14.04 but I don't know will this work. Any ideas ?

Will this really work ? I don't loose data I have on my windows
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user3581394Apr 28 '14 at 13:34

I did many installations (20 or more?) using this. It will work. And as you're using windows 7, it will be really easy. Just don't touch the windows partition. The first time you will boot Windows 7 after the installation, it will do chkdsk, don't worry.
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LittleNoobyApr 28 '14 at 13:39

You can upgrade from 12.04 LTS to 14.04 LTS. Open Software Updater and let it check for all updates. When it is done, it should inform you that there is a new version of Ubuntu available, and give you an option to upgrade.

If not, check the Software & Updates under the Updates tab there is a dropdown list at the bottom for Notify Me Of New Ubuntu Versions; select Long Term Support versions and then exit the window. Restart Software Updater let it run again. You should now be informed of a new version which you may upgrade to.

Wubi isn't no longer available (what I've heard on the Forums a time ago).

It is more advisable to set up a normal dual boot system;
you'll get:

increased performance

more stable Ubuntu

a handy way to fix W7 should a problem occur

a very easy way to handle files fromout 2 operating systems

To be short: Wubi was a way to install Ubuntu alongside Windows, but it is vunerable since Windows can have its issues what could lead that you can't bootup your Ubuntu.
So, a dual boot with separate partitions is a more plausible way of working with Ubuntu.

The installer is very easy to use, and choosing partition-sizes is also very easy. Please refer to the Wiki of Ubuntu should extra help be nessecary.